KR20140023348A - Process to produce an acylated vinylamine-containing polymer and its application as a papermaking additive - Google Patents

Abstract

Disclosed are methods of making acylated vinylamine-containing polymers. Acylated vinylamine-containing polymers are prepared by reacting a vinylamine-containing polymer with at least one acylating agent.

Description

Process for preparing acylated vinylamine-containing polymer and its use as an additive for papermaking {PROCESS TO PRODUCE AN ACYLATED VINYLAMINE-CONTAINING POLYMER AND ITS APPLICATION AS A PAPERMAKING ADDITIVE}

The present invention relates to a process for preparing acylated vinylamine-containing polymers via acylation of primary and secondary amines of vinylamine-containing polymers using an acylating agent such as acyl anhydride or acyl chloride. In particular, the present invention relates to a process for preparing acylated poly (vinylamine) derivatives using acetic anhydride or propionic anhydride. Moreover, the present invention relates to the use of acylated poly (vinylamine) derivatives as dry strength additives, wet strength additives, retention aids, drainage aids, and pitch and tack control agents in papermaking applications.

Poly (vinylamine) has been used in many industrial and pharmaceutical applications. In the paper industry, poly (vinylamine) products have been used as dry and wet strength additives to improve paper and paperboard strength, and as retention / drainage aids to improve paper productivity. US Pat. No. 2,721,140 originally disclosed the use of poly (vinylamine) molecules as additives for papermaking to improve paper wet strength. US Pat. No. 4,421,602 discloses partially hydrolyzed polymers of poly ( N -vinylformamide) for improving agglomeration, particulate retention and pulp drainage in papermaking. US Pat. No. 6,159,340 describes the use of partially hydrolyzed poly (vinylamine) products as dry and wet strength additives for paperboard. US Pat. Nos. 6,616,807 and 6,797,785 describe various poly (vinylamine) derivatives as paper drainage aids, flocculants, and retention aids. US Pat. No. 5,961,782 discloses the use of poly (vinylamine) to make crosslinkable creping adhesives.

Poly (vinylamine) is a linear cationic polymer with minimal branching, which contains one amine function every two carbon units. Partially hydrolyzed poly (vinylamine) may contain primary amine, amide and amidine functional groups. Poly (vinylamine) is typically prepared by conducting free-radical solution polymerization of N -vinylformamide monomers followed by base- or acid-catalyzed hydrolysis. US Pat. No. 4,275,002 discloses a process for preparing poly (vinylamine) using N -vinylacetamide monomers, followed by free-radical polymerization followed by hydrolysis with photoacids. US Pat. No. 4,774,285 describes the preparation of copolymers of N -vinylformamide and vinyl alcohol. US Patent No. 5,630,907 discloses copolymers of vinylamine and acrylic acid. US Pat. No. 6,797,785 discloses the preparation of copolymers of vinylamine and diallyldimethylammonium chloride and copolymers of vinylamine and acrylamide via reverse emulsion polymerization, and use as a coagulant and coagulant for papermaking. EP 0251182 describes the use of copolymers of vinylamine and acrylonitrile for papermaking as wet end additives, retention aids, and drainage aids for increasing paper strength.

US Patent Application No. 20090314446 describes a process for the preparation of amidine low content poly (vinylamine) and the use of such polymers for increasing retention and drainage rates and improving paper dry strength in papermaking processes, and other applications.

The amine functional group (either primary amine or amidine) of the poly (vinylamine) can react with various compounds having reactive functional groups. Post-polymerization chemical modification of poly (vinylamine) with compounds having functional groups is an alternative approach for producing poly (vinylamine) derivatives having altered or improved chemical, physical and application properties. U.S. Patent 5,292,441 describes the use of quaternized poly (vinylamine) as flocculant for wastewater purification, where quaternized poly (vinylamine) is used to convert poly (vinylamine) to alkylating agents such as methyl chloride, dimethyl sulfate or benzyl chloride. Obtained by reaction with. U. S. Patent 5,994, 449 describes resin compositions as reaction products of epihalohydrin with mixtures of poly (vinylamine-co-vinyl alcohol) and poly (aminoamides), and the use of such resins as creping adhesives.

More recently, US Pat. No. 7,902,312 discloses various Michael addition reaction adducts of poly (vinylamine), and the use of these modified poly (vinylamine) as dry strength additives and / or retention / drainage aids for papermaking. U.S. Patent Application Nos. 20090043051 and 20100193148 describe a number of modified poly (vinylamine) products prepared by alkylation, acylation and condensation reactions of poly (vinylamine) with various amine-reactive compounds. In these two patent applications, the amine groups of the vinylamine-containing polymers are substituted with cationic, anionic, hydrophobic and hydrophilic functional groups, or a combination of such functional groups. The use of such modified poly (vinylamine) products as pitch and sticky control agents as well as paper dry strength additives, retention and drainage aids in papermaking applications is also described.

As mentioned in the prior art, poly (vinylamine) derivatives also use N -vinylacetamide monomers to hydrolyze acetamide functional groups following free-radical solution polymerization to liberate free amine groups on the polymer backbone and release acetic acid. By release. The disadvantage of this prior art is that it requires expensive and unpurchased monomers for industrial production. Additionally, the poly (N- vinyl acetamide) is the water poly- more stable than (N-vinylformamide), and thereby more resistant to hydrolysis.

The present invention relates to acylated poly (vinylamine), in particular acetylated poly, using readily available acylating agents such as acyl anhydride, or acyl chlorides, preferably acetic anhydride, propionic anhydride, acetyl chloride and propionyl chloride It relates to a new method for producing (vinylamine). Acylation of poly (vinylamine) with acetic anhydride or propionic anhydride or acetyl chloride can be completed with high reaction efficiency without by-products except acetic acid, propionic acid, acetic chloride or propionic acid chloride, respectively.

Brief Description of the Invention

The present invention provides a process for preparing an acylated vinylamine-containing polymer, the method comprising reacting an acylating agent with a vinylamine-containing polymer. In particular, the process of the present invention provides a process for preparing acylated poly (vinylamine) by reacting acyl anhydride or acyl chloride with a poly (vinylamine) homopolymer.

Acetic anhydride or propionic anhydride can be reacted with poly (vinylamine) in a desired ratio of amine content of acyl anhydride to poly (vinylamine) to produce an acylated poly (vinylamine) polymer. This product has different chemical, physical and application properties compared to unmodified poly (vinylamine). In the case of poly (vinylamine) homopolymers, the primary amine of the poly (vinylamine) is converted to an amide bond via an acylation reaction. When acetic anhydride is used, acetamide functionality is formed on the backbone of the poly (vinylamine). Unlike formamide functionality in partially hydrolyzed poly ( N -vinylformamide), which is predominantly present as cyclized amidine, acetamide groups in this polymer react much more slowly with adjacent primary amines, resulting in corresponding amidine functionality. Form.

In the process of the invention, the vinylamine-containing polymer is preferably in an amount in the range of 2 to 50% by weight, preferably in an amount in the range of 5 to 40% by weight, most preferably based on the total weight of the polymer solution. It is dissolved in water in an amount ranging from 8 to 20% by weight.

The molar ratio of acylating agent to amine content of the vinylamine-containing polymer is from 1 to 200 mol%, preferably from 5 to about 100 mol%, most preferably from about 15 to 50 mol%.

The method is preferably performed at a reaction temperature of about 24 ° C. to about 80 ° C., more preferably about 30 ° C. to about 50 ° C., and most preferably about 35 ° C. to about 40 ° C. The method comprises about pH 5 to about 12.5; Preferably from about pH 6 to about 12; More preferably in a pH range of about 7 to about 11, most preferably about 8 to about 10.

The method is preferably performed for a period of about 0.1 to about 4 hours, more preferably about 0.5 to about 3 hours, most preferably about 1 to about 2 hours.

The molecular weight ( M _w ) of the vinylamine-containing polymer used in the present invention is in the range of 2,000 to 2,000,000 Daltons, preferably 4,000 to 1,000,000 Daltons, more preferably 10,000 to 1,000,000 Daltons, most preferably 50,000 to 500,000 Daltons Range. Accordingly, the acylated vinylamine-containing polymers of the present invention have a molecular weight range in the range of 3,000 to 2,000,000 Daltons, preferably 5,000 to 1,000,000 Daltons, more preferably 12,000 to 1,000,000 Daltons, most preferably 50,000 to 500,000 Daltons.

The acylated vinylamine-containing polymers of the present invention have a dry strength to increase retention of particulates and fillers by pulp fibers during the papermaking process, to accelerate drainage of pulp fibers, and to improve paper and paperboard dry strength. It can be used in papermaking as an additive.

When the acylated vinylamine-containing polymer of the present invention is added to the wet part of a paper machine based on an equivalent active polymer, it is a paperboard product made of an unmodified vinylamine-containing polymer, relative to the paperboard product. Provided improved dry strength properties as compared to. More specifically, the acetylated poly (vinylamine) product of the present invention was more effective at treatment levels of 0.01% to about 0.5% by weight based on the weight of dry pulp relative to unmodified poly (vinylamine). The product also provided good drainage and retention properties for the pulp fibers.

DESCRIPTION OF THE INVENTION

The present invention relates to a process for preparing an acylated vinylamine-containing polymer by reacting at least one acylating agent with a vinylamine-containing polymer, wherein the acylating agent is selected from the group consisting of acyl anhydrides, acyl halides, and mixtures thereof. .

The present invention relates to an acylated vinylamine-containing polymer having a) obtaining an aqueous solution comprising at least one vinylamine-containing polymer, and b) reacting the vinylamine-containing polymer with at least one acylating agent. It provides a manufacturing method. Preferred acylating agents include acyl anhydrides, acyl halides and mixtures thereof.

The method of the present invention is a method that offers advantages over existing methods of preparing acylated vinylamine-containing polymers. This method of the present invention uses a low-cost and commercially available acylating agent to modify widely available vinylamine-containing polymers to produce acylated vinylamine-containing polymers. This is different from the prior art which uses expensive and not commercially available monomers containing the same acyl groups to produce such polymers via polymerization. Poly (vinylamine) is widely available because the monomeric N -vinylformamide is relatively inexpensive and commercially available, and the hydrolysis of formamide groups is much faster than other amide groups that can be used in the process. Moreover, the process of the present invention produces acylated vinylamine-containing polymers with the desired level of acyl substitution by applying an appropriate amount of acylating agent, while in the prior art, the acylated vinylamine-containing polymers under harsh processing conditions It is more difficult to control the ratio through hydrolysis.

The process of the present invention provides a simplified process for preparing acylated vinylamine-containing polymers with high purity. The method produces no byproducts other than the relevant carboxylic acid when acyl anhydride is used and has no side reactions.

The process of the invention produces an acylated vinylamine-containing polymer comprising formula (I).

<Formula I>

Wherein R is preferably an alkyl or aryl group, more preferably -CH ₃ , -CH ₂ CH ₃ or -CH ₂ CH ₂ CH ₃ , most preferably -CH ₃ .

Specifically, the process of the present invention provides an acylated vinylamine-containing polymer by reacting at least one acylating agent with the primary and / or secondary amines of the vinylamine-containing polymer to form stable amide functional groups on the polymer backbone. do.

In one embodiment of the present invention, there is provided a process for the preparation of acylated poly (vinylamine), the process comprising performing free radical polymerization of N- vinylformamide in an aqueous solution followed by alkali hydrolysis to obtain poly ( Vinylamine), and reacting the polyvinylamine with an acylating agent.

Acylating agents used in the present invention include acyl anhydrides and acyl halides. For the purposes of the present invention, acyl anhydrides do not include cyclic anhydrides. Acylating agents used in the present invention include anhydrides such as acetic anhydride, propionic anhydride, butyric anhydride, heptanoic anhydride, anhydride, benzoic anhydride, phenylacetic anhydride, crotonic anhydride, chloroacetic anhydride, dichloroacetic anhydride and trifluoroacetic anhydride ; And carboxylic acid chlorides or bromides such as acetyl chloride, propionyl chloride, butyryl chloride, heptanoyl anhydride, benzoyl chloride, phenylacetyl chloride, crotonyl chloride, chloroacetyl chloride, or mixtures thereof. .

More preferably, the acylating agents used in the present invention include, but are not limited to, acetic anhydride, propionic anhydride, acetyl chloride, propionyl chloride, chloroacetyl anhydride, or mixtures thereof.

Vinylamine-containing polymers used in the present invention include partially or fully hydrolyzed poly ( N- vinylformamide); Copolymers of N -vinylformamide and vinylamine; Copolymers of vinylamine and amidine; Copolymers of N- vinylacetamide and vinylamine; Terpolymers of N- vinylformamide, vinylamine and amidine; Terpolymers of N- vinylformamide, vinylamine and vinylamine methyl chloride quaternary ammonium salts; Terpolymers of N- vinylformamide, vinylamine and vinyl alcohol; Terpolymers of N- vinylformamide, vinylamine and vinyl acetate; Terpolymers of N- vinylformamide, vinylamine and acrylamide; Terpolymers of N- vinylformamide, vinylamine and acrylate; Terpolymers of N- vinylformamide, vinylamine and diallyldimethyl ammonium chloride; Terpolymers of N- vinylformamide, vinylamine and vinyl trimethoxysilane; Or mixtures thereof, but is not limited to such.

Vinylamine-containing polymers used in the present invention also include alkylated vinylamine-containing polymers prepared by reacting a vinylamine-containing polymer with an alkylating agent. Alkylating agents containing amine-reactive functional groups include methyl chloride, ethyl chloride, propyl chloride, butyl chloride, benzyl chloride, phenylethyl chloride, allyl chloride, 2- (diethylamino) ethyl chloride, 2- (dimethylamino) ethyl chloride, 3-Chloro-2-hydroxypropyltrimethylammonium chloride, 3-chloro-2-hydroxypropyl-lauryl-dimethylammonium chloride, 3-chloro-2-hydroxypropyl-cocoalkyl-dimethylammonium chloride, 3-chloro 2-hydroxypropyl-stearyl-dimethylammonium chloride, (4-chlorobutyl) trimethylammonium chloride, (6-chlorohexyl) trimethylammonium chloride, (8-chlorooctyl) trimethylammonium chloride, (glycidylpropyl) Trimethylammonium chloride, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, hexadecyl glycidyl ether, Salts of C12 / C14 glycidyl ether, chloroacetamide, chloroacetic acid or bromoacetic acid, or mixtures thereof, but are not limited thereto.

Vinylamine-containing polymers used in the present invention also include aldehyde-reacted vinylamine-containing polymers prepared by reacting a vinylamine-containing polymer with an aldehyde-containing compound. Aldehyde-containing compounds include acetaldehyde, propionaldehyde, butylaldehyde, glyoxal, monosaccharides or oligosaccharides having aldehyde reducing ends (e.g. glucose, maltose, lactose, maltodextrin, corn syrup, enzymatically hydrolyzed) Starch or guar, chemically hydrolyzed starch or guar, or mixtures thereof), but is not limited thereto.

Vinylamine-containing polymers used in the present invention also include amphoteric vinylamine-containing polymers prepared by reacting a vinylamine-containing polymer with a cyclic anhydride via a ring opening reaction of the cyclic anhydride. Cyclic anhydrides include succinic anhydride, maleic anhydride, glutaric anhydride, 3-methylglutaric anhydride, 2,2-dimethylsuccinic anhydride, cyclic alkyl carboxylic anhydride, cyclic alkenyl carboxylic anhydride, al Kenyl succinic anhydride (ASA), phthalic anhydride or mixtures thereof, including but not limited to.

Vinylamine-containing polymers used in the present invention also include Michael adducts of vinylamine-containing polymers prepared by reacting a vinylamine-containing polymer with a compound having an α, β-unsaturated bond conjugated to an electron withdrawing group. Such compounds include acrylamide, methacrylamide, t -butyl acrylamide, N- alkylacrylamide, N- alkylmethacrylamide, N- [3- (propyl) trimethylammonium chloride] acrylamide, N- [3- ( Propyl) trimethylammonium chloride] methacrylamide, methyl acrylate, alkyl acrylate, methyl methacrylate, alkyl methacrylate, aryl acrylate, aryl methacrylate, [2- (methacryloyloxy) ethyl]- Trimethylammonium chloride, N- [3- (dimethylamino) propyl] acrylamide, N- [3- (dimethylamino) propyl] methacrylamide, N -ethylacrylamide, 2-hydroxyethyl acrylate, acrylonitrile , Vinylpyridine, 1-vinyl-2-pyrrolidinone, or mixtures thereof, but is not limited thereto.

More preferably, the vinylamine containing polymers used in the present invention include partially or fully hydrolyzed poly ( N- vinylformamide); Copolymers of vinylamine and amidine; Terpolymers of N- vinylformamide, vinylamine and amidine; Terpolymers of N- vinylformamide, vinylamine and acrylate; Terpolymers of N- vinylformamide, vinylamine and diallyldimethyl ammonium chloride; Terpolymers of N- vinylformamide, vinylamine and vinyl alcohol; Alkylated vinylamine-containing polymers, wherein the alkylating agent is allyl chloride, or alkyl glycidyl ether; Monosaccharide- or oligosaccharide-reacted vinylamine-containing polymers; Or Michael adducts of vinylamine-containing polymers, including but not limited to.

The active polymer in the solution of the vinylamine-containing polymer of the invention represents the total weight as a percentage in the solution of all monomers, acylating agents and other amine-reactive compounds used in the preparation of the acylated vinylamine-containing polymer on a dry basis. For example, N-vinylformamide is a monomer precursor for poly (vinylamine) and has a molecular weight of about 71.1. As an example, a 100 g poly (vinylamine) solution containing a polymer originally prepared with 7.11 g of N-vinylformamide has a 7.11% active polymer. As an example, then 100 g of acetylated poly (vinylamine) solution containing 10 g of N-vinylformamide and 4 g of acetic anhydride will have 14% active polymer.

The amine content of a vinylamine-containing polymer is the amount of vinylamine in the polymer in a predetermined amount of product, calculated on a molar basis. This can be calculated by multiplying the weight percentage of active polymer in solution x weight percentage of N -vinylformamide in the active polymer (based on starting material) x weight of product and dividing by the molecular weight of N -vinylformamide (MW = 71.08). For homopolymers, the weight percentage of n-vinylformamide is 100%. For example, using 100 g of a 15% active polymer solution of homopolymer, the calculation would be (0.15 active material) (100 g) /71.08. For example, using 100 g of a 15% active polymer solution of a 50:50 copolymer, the calculation would be (0.15 active material) (0.5 parts of vinylformamide in the polymer) (100 g) /71.08. The active polymer of the vinylamine-containing polymer product is defined as the total weight (in percentage) in the product of all monomers, modifiers and other amine-reactive compounds used in the preparation of the vinylamine-containing polymer on a dry basis. Commercially, vinylamine-containing polymers often use N -vinylformamide as the starting monomer. If different starting monomers are used to prepare the vinylamine-containing polymer, then similar calculations can also be made using the molecular weight of the starting monomer instead of the molecular weight (71.08) of the N -vinylformamide.

In the present invention, the molar ratio of the acylating agent to the amine content of the vinylamine-containing polymer may be about the same. However, the reaction can be carried out in stoichiometric imbalance. Depending on the desired level of acylation, the molar ratio of the acylating agent to the amine content of the vinylamine-containing polymer is 1 to 200 mol%, preferably 5 to about 100 mol%, most preferably about 15 to 50 mol%. The efficiency of the acylation reaction varies depending on the type of acylating agent and the reaction conditions. When the reaction efficiency is less than 50%, the amine content of the acylating agent to vinylamine-containing polymer may need to be at least 200 mol%. The reaction efficiency of acetic anhydride or propionic anhydride with poly (vinylamine) is about 70-98%, while the reaction efficiency of acetyl chloride with the same poly (vinylamine) ranges from 40-80%.

The molecular weight of the vinylamine-containing polymer has little effect on the acylation efficiency. While not intending to be bound by theory, the molecular weight of the acylated vinylamine-containing polymers of the present invention is important for its use as a papermaking addition for improving the strength of paper products. If the molecular weight is too low, the vinylamine-containing polymer may have a poor retention for pulp fibers. If the molecular weight is too high, the vinylamine-containing polymer may tend to aggregate pulp, which may reduce the effectiveness of the polymer as a strength additive. The molecular weight (M _w ) of the vinylamine-containing polymer used in the present invention is in the range of 2,000 to 2,000,000 Daltons, preferably 4,000 to 1,000,000 Daltons, more preferably 10,000 to 1,000,000 Daltons, most preferably 50,000 to 500,000 Daltons Range.

Accordingly, the acylated vinylamine-containing polymer of the present invention has a molecular weight in the range of 3,000 to 2,000,000 Daltons, preferably 5,000 to 1,000,000 Daltons, more preferably 12,000 to 1,000,000 Daltons, most preferably 50,000 to 500,000 Daltons. Have

In the process of the invention, the weight percentage of the vinylamine-containing polymer in water and the molecular weight of the polymer dominate the solution viscosity properties. The higher the molecular weight of the vinylamine-containing polymer, the higher the viscosity of the aqueous polymer solution at the same weight percentage of the vinylamine-containing polymer, so that the polymer solution must be diluted further to facilitate pumpability or to prevent gelation. do. High solution viscosity can interfere with the uniform reaction between the acylating agent and the vinylamine-containing polymer due to inefficient mass transfer. The vinylamine-containing polymer used in the present invention is in an amount in the range of 2 to 50% by weight, preferably in an amount in the range of 5 to 40% by weight, most preferably 8 to 20% by weight, based on the total weight of the polymer solution. Soluble in water in amounts ranging from%. Preferably, the weight percentage of partially or fully hydrolyzed poly ( N -vinylformamide) is in the range of 8-20% in water.

Preferably, the vinylamine-containing polymer used in the present invention is dissolved in water in the absence of an organic solvent. However, the vinylamine-containing polymers used in the process can also be dissolved in a mixture of water and one or more water miscible organic solvents. Examples of water miscible solvents include, but are not limited to, ethanol, ethylene glycol, glycerol ethanol, isopropanol, formic acid, acetic acid and their sodium or potassium salts.

The process of the present invention is preferably from about 10 ° C to about 80 ° C, preferably from about 20 ° C to about 50 ° C, more preferably from about 24 ° C to about 50 ° C, most preferably from about 35 ° C to about 40 ° C. Is carried out at a reaction temperature of. If the temperature of the acylation reaction is too high, the acylating agent, for example acetic anhydride or acetyl chloride, may undergo hydrolysis in water before it reacts with the vinylamine-containing polymer.

One vinylamine-containing polymer is typically a poly (vinylamine) prepared by free radical polymerization of an N- vinylformamide monomer followed by base-hydrolysis to deprotect the primary amine and liberate formic acid. to be. Partially hydrolyzed poly ( N- vinylformamide) contains N- vinylformamide, amidine and vinylamine units. These fully and partially hydrolyzed poly ( N- vinylformamide) polymers can be acylated directly by the process of the invention after the polymer solution has been adjusted to the appropriate pH with acid. Acids used for pH adjustment include, but are not limited to, hydrochloric acid, sulfuric acid, acetic acid and formic acid, or mixtures thereof. However, it should be noted that sulfuric acid can cause precipitation of acylated vinylamine-containing polymers depending on the degree of acylation, with the most preferred acids being hydrochloric acid, acetic acid and formic acid.

The process of the invention is carried out at a pH in the range of pH 5 to about 12.5; Preferably in the range of about pH 6 to about 12; More preferably in the range of about 7 to about 11, most preferably in the range of about 8 to about 10. Above pH 11, acylating agents, such as acetic anhydride, can be hydrolyzed in water faster than its reaction with vinylamine-containing polymers. Partially or fully hydrolyzed poly ( N- vinylformamide) must be fully protonated at acidic pH (pH 4.0 or lower) due to cationic charge repulsion; Thus, it may still have free primary available for acylation reactions under acidic conditions below pH 4. The reaction pH of the process can be controlled by gradually adding an alkali, such as sodium hydroxide solution, to neutralize the carboxylic acid or halide ions liberated during the acylation reaction.

The method of the present invention is preferably performed from about 0.1 to about 4 hours, more preferably from about 0.5 to about 3 hours, most preferably from about 1 to about 2 hours. The reaction is usually fast for acylation of the vinylamine-containing polymer with acyl anhydride in water, but this is much faster when the acyl halide is an acylating agent.

In addition to the primary amine moiety, partially hydrolyzed poly ( N- vinylformamide) and vinylamine copolymers of the invention typically comprise randomly distributed amidine functional groups. The level of amidine functionality depends on hydrolysis conditions such as time, temperature, amount of caustic, and other factors. As a result, the acylation of the partially hydrolyzed poly ( N- vinylformamide) according to the invention with an acylating agent such as acetic anhydride can also take place on the nitrogen atom of the amidine functional group, as a result of Randomly distributed monomer units are produced.

The process of the present invention can provide acetylated poly (vinylamine) derivatives by reacting acetic anhydride with a poly (vinylamine) homopolymer at a predetermined ratio of the amine content of acetic anhydride to poly (vinylamine). Acetylated poly (vinylamine) derivatives have different chemical, physical and application properties compared to unmodified poly (vinylamine). Acetylated poly (vinylamine) derivatives of the present invention have a lower Brookfield viscosity than unmodified poly (vinylamine) when compared to equivalent activity criteria. When acetylated poly (vinylamine) derivatives were used as papermaking additives on an equivalent polymer active weight basis, this resulted in improved strength properties over poly (vinylamine) for paper and paperboard products made using papermaking machines. Provided. Acetylated poly (vinylamine) products were effective at treatment levels of 0.01% to about 0.5% by weight on a dry pulp basis. This product also gave the pulp fibers good drainage and retention properties.

According to US Patent Application No. 2009031444, amidine functional groups can adversely affect retention and drainage and dry strength enhancing performance in the papermaking process, with low amidine poly (vinylamine) being preferred. ¹ H-NMR and ¹³ C-NMR spectral analysis of acetylated poly (vinylamine) showed that acetamide functionality is present as the main functional group in the polymer, and very small amounts of acetamide are cyclized during processing and storage to amidine functionality. Appeared to form. Clearly, the acetamide groups of acetylated poly (vinylamine) react much more slowly than formamide groups to form the corresponding amidines. Formamide groups on partially hydrolyzed poly ( N- vinylformamide), or formylated (polyvinylamine) react quickly with adjacent primary amines to form amidine functional groups. At the same level of acylation, acetylated poly (vinylamine) will contain fewer amidine functional groups and more primary amine groups than partially hydrolyzed poly ( N- vinylformamide). While not wishing to be bound by theory, it is believed that the reduced amidine content in the presence of acetyl groups as compared to the higher amidine content in the presence of formamide leads to the observed improved performance.

The acylated vinylamine-containing polymers of the present invention can be used as dry strength additives for paper and paperboard products to increase retention of particulates and fillers by pulp fibers during the papermaking process, and to accelerate drainage of pulp fibers. .

Acylated polymers of the present invention may also be used in combination with other compositions to improve the properties of the polymer. Compositions that can be used in combination with the acylated vinylamine-containing polymers of the invention can be cationic, or anionic, or amphoteric, or nonionic synthetic or natural polymers. For example, the acylated vinylamine-containing polymers of the present invention can be used with cationic starch or amphoteric starch to improve the strength properties of paper products. The acylated vinylamine-containing polymers of the present invention also include anionic polymers such as polyacrylic acid, acrylamide and acrylic acid, or carboxymethyl cellulose to form polyelectrolyte complexes to improve the strength properties of the paper product; Cationic polymers such as crosslinked polyamidoamine, polydiallyldimethylammonium chloride, or polyamines. The acylated vinylamine-containing polymers of the present invention can also be used in combination with polymeric aldehyde-functional compounds such as glyoxalated polyacrylamide, aldehyde cellulose and aldehyde functional polysaccharides. Individual compositions or any combination of different compositions may be applied with the acylated vinylamine-containing polymer of the present invention or may be applied sequentially before or after application of the polymer of the present invention. Prior to use, the individual compositions can be blended with the acylated vinylamine-containing polymers of the present invention to form blended compositions.

Embodiments of the present invention are defined in the following examples. It should be understood that these embodiments are provided by way of example only. Accordingly, various modifications of the invention in addition to those shown and described herein will be apparent to those skilled in the art from the foregoing description. Although the invention has been described with reference to specific means, materials and embodiments, it is to be understood that the invention is not limited to the specific details disclosed and extends to all equivalents within the scope of the appended claims.

Example

Size exclusion chromatography (SEC) was used to determine molecular weight. Gel permeation column (CATSEC 4000 + 1000 + 300 + 100) and Waters 515 series chromatography using a mixture of 1% NaNO ₃ /0.1% trifluoroacetic acid in 50:50 H ₂ O: CH ₃ CN as mobile phase Analysis was performed using a grading instrument. The flow rate was 1.0 mL / min. The detector was a Hewlett Packard 1047A differential refractometer. Column temperature was set to 40 ° C. and detector temperature to 35 ° C. The number average (Mn) and weight average molecular weight (Mw) of the polymers were calculated relative to the narrow molecular weight standard poly (2-vinyl pyridine) available.

The charge density (Muetek) of the ionized polymers in the present invention was measured at pH 7.0 using colloid titration. The charge density (meq / g) is the amount of cationic charge per unit weight expressed in milliequivalents per gram of product solid. Polymer samples were titrated to 0 mV potential at a fixed titration rate (0.1 mL / min, 5 sec) using an autotitrator (Brinkmann Titrino) with potassium polyvinyl sulfate (PVSK), The end point was detected using a particle charge detector (Model PCD 03, BTG, Mutek Analytic Inc., Marietta Kingston Citi 2141, GA).

Brookfield viscosity (BV) was measured using a DV-II viscometer (Brookfield Viscosity Lab, Middleboro, Mass.). The selected spindle (number 2) was attached to the instrument set at a speed of 30 RPM. The reaction solution was prepared to a specific solids content. The Brookfield Viscosity Spindle was carefully inserted into the solution so as not to trap any air bubbles and then spun at 24 ° C. for 3 minutes at the above mentioned speed. The unit is centipoise (cp).

In all the examples below, high pH solutions of poly (vinylamine) homopolymers were used unless otherwise stated. This poly (vinylamine) solution was obtained after completing the free radical polymerization step and the base-hydrolysis step of N- vinylformamide, but this is the solution before neutralization with hydrochloric acid. This poly (vinylamine) product had 14.9% active polymer with a pH between about 11.5 and 12.5.

Example 1 Preparation of Acetylated (24.7 mol%) Poly (vinylamine) at Controlled pH

The poly (vinylamine) solution (14.9% active polymer, 322.7 g) in a 1 L reaction flask was neutralized to pH 9.0 with 36.5% HCl. Acetic anhydride (Aldrich Chemical Co., 16.9 g, 24.7 mol% based on the amine content of the poly (vinylamine)) ranges from 30 ° C. to 40 ° C. while maintaining the pH at 9.0 using NaOH solution. It was added over 10 minutes with stirring at the temperature of. The resulting mixture was stirred for 30 minutes at a temperature in the range of 30 ° C. to 40 ° C. and the pH was maintained at 9.0 using NaOH solution. After no further change in reaction pH, the reaction was cooled to room temperature and the pH was adjusted to 7.5 using 36.5% HCl, resulting in a final clear solution product of 25.5% total solids and 14.2% active polymer. Obtained. The charge density was determined to be 6.74 meq / g at pH 7.0. This product was a clear solution with a Brookfield viscosity of 1429 cp. SEC: M _w : 316,000; M _w / M _n : 4.25.

Example 2 Preparation of Acetylated (24.6 mol%) Poly (vinylamine) Without pH Control

Poly (vinylamine) solution (14.9% active polymer, 600.0 g) in a 2 L reaction flask was neutralized to pH 10.0 with 36.5% HCl. Acetic anhydride (Aldrich Chemical Company, 31.3 g, 24.4 mol% based on the amine content of the poly (vinylamine)) was added over 10 minutes with stirring at a temperature ranging from 30 ° C. to 40 ° C. For this example, the theoretical amine content of PVAm is 14.9% x 600 / 71.08 = 1.258 moles; Acetic anhydride is 31.3 / 102.09 = 0.307 mol; Thus, the mole percentage is 0.307 / 1.258 = 24.4 mole%. The resulting mixture was stirred for 30 minutes at a temperature ranging from 30 ° C. to 40 ° C. and the pH was reduced to 8.0. After there was no further reduction in reaction pH, the reaction was cooled without further pH adjustment to yield a final product with 27.0% total solids and 14.7% active polymer as calculated. The charge density was determined to be 6.82 meq / g at pH 7.0. This product was a clear solution and had a Brookfield viscosity of 1692 cps. SEC: M _w : 322,000; M _w / M _n : 4.39.

Examples 3-15

Examples 3 to 15 were prepared as described in Example 2 except that different mole% acetic anhydride was used for acetylation and the reaction was started at different pH. All solution products were apparently transparent.

<Table I>

Examples 16-18

Example 16 and Example 17 were prepared as described in Example 1 except that acetylation was performed at different temperatures. All solution products were apparently transparent.

<Table II>

Relative acylation efficiency can be assessed by determining the amount of acetic acid produced during the reaction for a series of reactions performed with the same mole% acetic anhydride to poly (vinylamine). This efficiency was calculated based on the amount of NaOH consumed to maintain the reaction pH at 10.0. The actual reaction efficiency should be higher because the reaction pH shifted to acidic when the primary amine group of the poly (vinylamine) was acetylated, with NaOH consumed to maintain the reaction pH as a result of the shifted to acidic. Can be more.

As shown in Table II, under these acetylation conditions, the acetylation efficiency was much higher at 92% at lower temperatures (20-28 ° C.) than at 61% at higher temperatures (70-75 ° C.).

Example 19 Preparation of Acetylated (26 Mole%) Poly (Vinylamine) Using Hercobond® 6363

Poly (vinylamine) solution (Hercobond® 6363 paper performance additives, available from Ashland Incorporated, 11.7% active polymer, 165 g, pH 8.0) in a 1 L reaction flask The pH was adjusted to 10.5 using NaOH solution. Acetic anhydride (Aldrich Chemical Company, 7.2 g, 26 mol% based on amine content of poly (vinylamine)) was added over 10 minutes at 30 ° C. with stirring. The resulting mixture was stirred at 40 ° C. for 30 minutes. After no further changes in pH, the solution was cooled to room temperature and the pH was adjusted to 7.5 with 36.5% HCl to give a final clear solution product with 23.9% total solids and 12.5% total active polymer. . The charge density was determined to be 6.65 meq / g at pH 7.0. This product was a clear solution with a Brookfield viscosity of 1168 cp. SEC: M _w : 315,000; M _w / M _n : 4.33. The reaction efficiency was calculated to be 89.5% using the titration method.

Example 20-Succinic anhydride acylation (3 mol%)-Acetylation (26 mol%) poly (vinylamine)

The poly (vinylamine) solution (14.9% active polymer, 145 g) in a 1 L reaction flask was neutralized to pH 11.0 with 36.5% HCl. Acetic anhydride (Aldrich Chemical Company, 8.1 g, 26 mol% based on the amine content of the poly (vinylamine)) was added to the solution with stirring over 10 minutes, followed by succinic anhydride (Aldrich Chemical Company, 1.0 g, poly 3 mole%), based on the amine content of (vinylamine), at 30 ° C. to 40 ° C. over 2 minutes. The resulting mixture was stirred at a temperature in the range of 24 ° C. to 40 ° C. for 30 minutes. After there was no further reduction in pH, the solution pH was adjusted to 8.0 with 36.5% HCl to give a final clear solution product with 27.9% total solids and 15.1% total active polymer. The charge density was determined to be 6.42 meq / g at pH 7.0. This product was a clear solution with a Brookfield viscosity of 1828 cps: SEC: M _w : 310,000; M _w / M _n : 3.07.

Example 21 maltodextrin coupled (0.6 mol%)-acetylated (20 mol%) poly (vinylamine)

The poly (vinylamine) solution (14.9% active polymer, 141 g) in a 1 L reaction flask was neutralized to pH 11.0 with 36.5% HCl. Maltodextrin dissolved in 30 g water (Maltrin M100, Grain Processing Corp., 3.0 g, 0.6 mol% based on amine content of poly (vinylamine)) at 40 ° C. for 10 minutes It was added to the solution with stirring over. The resulting mixture was stirred at 40 ° C. for 10 minutes, then acetic anhydride (Aldrich Chemical Company, 6.0 g, 20 mol% based on the amine content of the poly (vinylamine)) was added over 10 minutes with stirring. The resulting mixture was stirred for 30 minutes at a temperature ranging from 24 ° C. to 40 ° C. to give a final product having a total active polymer of 14.1% at pH 8.0. The charge density was determined to be 6.28 meq / g at pH 7.0. This product was a clear solution with a Brookfield viscosity of 1548 cps. SEC: M _w : 352,000; M _w / M _n : 3.38.

Example 22 lactose coupled (1.2 mol%)-acetylated (20 mol%) poly (vinylamine)

Poly (vinylamine) solution (14.9% active polymer, 180 g) in a 1 L reaction flask was neutralized to pH 11.0 with 36.5% HCl. Lactose (Aldrich Chemical Company, 1.5 g, 1.2 mol% based on amine content of poly (vinylamine)) dissolved in 10 g water was added to the solution with stirring at 40 ° C. over 10 minutes. The resulting mixture was stirred for 10 minutes at 40 ° C., then acetic anhydride (Aldrich Chemical Company, 7.7 g, 20 mol% based on the amine content of the poly (vinylamine)) was added over 10 minutes with stirring. The resulting mixture was stirred for 30 minutes at a temperature ranging from 24 ° C. to 40 ° C. to give a final product having a total active polymer of 10.0% at pH 8.0. This product was a clear solution with a Brookfield viscosity of 218 cp.

Example 23 Preparation of Propionylated (20 Mole%) Poly (vinylamine)

Poly (vinylamine) solution (14.9% active polymer, 130.0 g) in a 1 L reaction flask was neutralized to pH 10.0 with 36.5% HCl. Propionic anhydride (Aldrich Chemical Company, 7.2 g, 20 mol% based on amine content of poly (vinylamine)) was added over 10 minutes with stirring at a temperature in the range from 30 ° C. to 40 ° C. The resulting mixture was stirred at a temperature in the range of 30 ° C. to 40 ° C. for 30 minutes. The pH was adjusted to 7.4 with 36.5% HCl to give a final product with 21.4% total solids and 11.8% total active polymer. This product was slightly turbid and had a Brookfield viscosity of 1020 cps.

Example 24 Preparation of Acetylated (38 mol%) Poly (vinylamine) Using Acetyl Chloride

The poly (vinylamine) solution (14.9% active polymer, 133.0 g) in a 1 L reaction flask was neutralized to pH 9.0 with 36.5% HCl. Acetyl chloride (Aldrich Chemical Company, 8.3 g, 38 mol% based on amine content of poly (vinylamine)) was added dropwise over 20 minutes with stirring at a temperature in the range of 23 ° C to 30 ° C. The reaction was violent and immediate. The resulting mixture was stirred for 30 minutes at a temperature ranging from 23 ° C. to 35 ° C. to give a final product at pH 6.7 of 24.0% total solids and 13.1% active polymer. This product was a clear solution with a Brookfield viscosity of 1120 cp.

Example 25-Allyl Chloride Alkylation (10 mol%)-Acetylation (17 mol%) Poly (vinylamine)

The amine content of allyl chloride (Aldrich Chemical Company, 2.5 g, poly (vinylamine)) over 5 minutes at 60 ° C. in a poly (vinylamine) solution (14.9% active polymer, 149 g) in a 1 L reaction flask at pH 12.1. 10 mole%) as standard. The resulting mixture was stirred for 2 h at 60 ° C. and then cooled to 40 ° C. with 36.5% HCl adjusting the pH to 11.0. Acetic anhydride (Aldrich Chemical Company, 5.4 g, 17 mol% based on the amine content of the poly (vinylamine)) was added over 10 minutes with stirring. The resulting mixture was stirred at a temperature in the range of 24 ° C. to 40 ° C. for 50 minutes. The pH was adjusted to 8.0 with 36.5% HCl to give a final product with 14.0% total active polymer. This solution product was cloudy with a Brookfield viscosity of 1252 cps. SEC: M _w : 308,000; M _w / M _n : 4.71.

Example 26-Chloroacetamide Alkylation (3.4 mol%)-Acetylation (22.6 mol%) poly (vinylamine)

Amine content of chloroacetamide (Aldrich Chemical Company, 1.0 g, poly (vinylamine)) over 5 minutes at 40 ° C. in a poly (vinylamine) solution (14.9% active polymer, 150 g) in a 1 L reaction flask at pH 12.1. 3.4 mole%) was added. The resulting mixture was stirred for 30 minutes at 40 ° C. and then cooled to 30 ° C. while adjusting the pH to 11.0 with 36.5% HCl. Acetic anhydride (Aldrich Chemical Company, 7.25 g, 22.6 mol% based on the amine content of the poly (vinylamine)) was added over 10 minutes with stirring. The resulting mixture was stirred at a temperature ranging from 24 ° C. to 40 ° C. for 40 minutes. The pH was adjusted to 7.75 with 36.5% HCl to give a final product with 13.4% total active polymer. This product was a clear solution with a Brookfield viscosity of 1756 cp. SEC: M _w : 318,000; M _w / M _n : 4.55.

Example 27-(3-acrylamidopropyl) trimethylammonium chloride alkylation (20 mol%)-acetylation (10 mol%) poly (vinylamine)

Poly (vinylamine) solution (Hercobond® 6363 paper performance additives, available from Ashland Incorporated, 11.7% active polymer, 250 g, pH 8.0) in a 1 L reaction flask with 50% NaOH solution (16.9 g ) To pH 11.5. (3-acrylamidopropyl) -trimethylammonium chloride (APTAC, 60% solution in water, available from Ashland Incorporated, 21.27 g, 20 mol% based on amine content of poly (vinylamine)) It was added to a poly (vinylamine) solution, which was then heated to 70 ° C. The solution was stirred with heating at 70 ° C. for 3 hours and then cooled to 50 ° C. Acetic anhydride (Aldrich Chemical Company, 6.30 g, 10 mol% based on amine content of poly (vinylamine)) was added and the solution was stirred at 50 ° C. for an additional 3 hours. The solution was cooled and the pH was adjusted to 8.3 with 36.5% HCl to give a final clear solution product with 26.9% total solids and 15.5% total active polymer. The charge density was determined to be 7.97 meq / g at pH 7.0. This product was a clear solution with a Brookfield viscosity of 1166 cp. SEC: Mw: 350,000; Mw / Mn: 3.83.

Example 28-(3-acrylamidopropyl) trimethylammonium chloride alkylation (10 mol%)-acetylation (15 mol%) poly (vinylamine)

Poly (vinylamine) solution (Hercobond® 6363 Paper Performance Additives, available from Ashland Incorporated, 11.7% active polymer, 250 g, pH 8.0) in a 1 L reaction flask with 50% NaOH solution (16.5 g ) To pH 11.5. (3-acrylamidopropyl) -trimethylammonium chloride (APTAC, 60% solution in water, available from Ashland Incorporated, 28.35 g, 10 mol% based on amine content of poly (vinylamine)) It was added to a poly (vinylamine) solution, which was then heated to 70 ° C. The solution was stirred with heating at 70 ° C. for 3 hours and then cooled to 50 ° C. Acetic anhydride (Aldrich Chemical Company, 4.20 g, 15 mol% based on amine content of poly (vinylamine)) was added and the solution was stirred at 50 ° C. for an additional 3 hours. The solution was cooled and the pH was adjusted to 8.3 with 36.5% HCl to give a final clear solution product with 26.9% total solids and 16.1% total active polymer. The charge density was determined to be 8.16 meq / g at pH 7.0. This product was a clear solution with a Brookfield viscosity of 1116 cps.

Example 29-(3-acrylamidopropyl) trimethylammonium chloride alkylation (15 mol%)-acetylation (15 mol%) poly (vinylamine)

Poly (vinylamine) solution (Hercobond® 6363 paper performance additive, available from Ashland Incorporated, 11.7% active polymer, 250 g, pH 8.0) in a 1 L reaction flask was added with a 50% NaOH solution (17.05 g ) To pH 11.5. (3-acrylamidopropyl) -trimethylammonium chloride (APTAC, 60% solution in water, available from Ashland Incorporated, 21.27 g, 15 mol% based on the amine content of poly (vinylamine)) It was added to a poly (vinylamine) solution, which was then heated to 70 ° C. The solution was stirred with heating at 70 ° C. for 3 hours and then cooled to 50 ° C. Acetic anhydride (Aldrich Chemical Company, 4.20 g, 15 mol% based on amine content of poly (vinylamine)) was added and the solution was stirred at 50 ° C. for an additional 3 hours. The solution was cooled and the pH was adjusted to 8.3 with 36.5% HCl to give a final clear solution product with 26.2% total solids and 15.0% total active polymer. The charge density was determined to be 8.64 meq / g at pH 7.0. This product was a clear solution with a Brookfield viscosity of 1022 cps.

Example 30-Access B: (3-acrylamidopropyl) trimethylammonium chloride alkylation (20 mol%)-acetylation (10 mol%) poly (vinylamine)

Poly (vinylamine) solution (Hercobond® 6363 paper performance additive, available from Ashland Incorporated, 11.7% active polymer, 250 g, pH 8.0) in a 1 L reaction flask was added with a 50% NaOH solution (12.4 g ) To pH 10.1. Acetic anhydride (Aldrich Chemical Company, 4.20 g, 10 mol% based on amine content of poly (vinylamine)) was added and the solution was stirred at 50 ° C. for 3 hours. The solution was followed by 50% NaOH (4.65 g) followed by (3-acrylamidopropyl) trimethylammonium chloride (APTAC, 60% solution in water, available from Ashland Incorporated, 14.18 g, poly (vinylamine) 20 mol%) based on the amine content of. The solution was heated to 70 ° C. and stirred for an additional 3 hours. The solution was cooled to room temperature and the pH was adjusted to 9.1 with 36.5% HCl to give a final clear solution product with 27.6% total solids and 14.3% total active polymer. The charge density was determined to be 8.37 meq / g at pH 7.0. This product was a clear solution with a Brookfield viscosity of 942 cp.

Example 31 Biguanidinylation (5 mol%)-Acetylation (25 mol%) poly (vinylamine)

Poly (vinylamine) solution (Hercobond® 6363 paper performance additives, available from Ashland Incorporated, 11.7% active polymer, 250 g, pH 8.0) in a 1 L reaction flask with 50% NaOH solution (10.8 g ) To pH 10.1. Acetic anhydride (Aldrich Chemical Company, 10.50 g, 25 mol% based on amine content of poly (vinylamine)) was added and the solution was stirred at 50 ° C. for 3 hours. The solution was treated with 50% NaOH (9.00 g) followed by dicyandiamide (Aldrich Chemical Company, 1.75 g, 5 mol% based on the amine content of poly (vinylamine)). The solution was heated to 100 ° C. and stirred for an additional 3 hours. The solution was cooled to room temperature and the pH was adjusted to 7.6 with 36.5% HCl to give a final clear solution product with 25.8% total solids and 14.0% total active polymer. The charge density was determined to be 7.33 meq / g at pH 7.0. This product was a clear solution with a Brookfield viscosity of 394 cp.

Example 32 Evaluation as a Dry Strength Additive in Papermaking Applications

The dry strength of the paper made from the poly (vinylamine) derivatives of the above examples was determined using the benchmark dry strength resin poly (vinylamine) (Hercobond® 6363 paper performance additive, available from Hercules Incorporated). It was compared with the dry strength of.

Linerboard paper was made using a paper machine. Paper pulp was 100% recycled media with 50 ppm hardness, 25 ppm alkalinity, 2.5% GPC D15F and 2000 uS / cm conductivity. The system pH was 7.0 and the pulp freeness was 350-420 CSF at a stock temperature of 52 ° C. Basis weight was 100 lbs per 3000 ft ² . The poly (vinylamine) derivatives prepared in this example were added as dry strength agents to the wet part of the papermaking machine at an active polymer level of 0.3% by weight relative to dry paper pulp. Dry strength effect was measured using dry tensile strength, Ring Crush and Mullen Burst.

The dry strength test results are shown in Table III below. The performance of poly (vinylamine) derivatives is expressed as a percentage increase in dry strength of paper made with poly (vinylamine) (Hercobond® 6363 Paper Performance Additive, available from Hercules Incorporated).

<Table III>

Table III compares representative polymers of the present invention with poly (vinylamine) (Hercobond® 6363). All of the acylated poly (vinylamine) derivatives evaluated provided improved mulene rupture over unmodified poly (vinylamine) (Hercobond® 6363) on an equivalent activity basis. All acylated poly (vinylamine) derivatives also provided better dry tensile and ring crush equivalents (within 2%) or better than unmodified Hercobond® 6363. For example, acetylated PVAm (27%) (Example 8) improved mullen rupture to 10.4%, ring crush to 6.6% and dry tensile to 7.2% compared to benchmark Hercobond® 6363. In addition, it should be noted that all acylated poly (vinylamine) derivatives are less expensive to manufacture and have improved cost effectiveness compared to Hercobond® 6363 on an activity basis compared to unmodified poly (vinylamine).

Claims (17)

a. Obtaining an aqueous solution comprising at least one vinylamine-containing polymer, and
b. Reacting the vinylamine-containing polymer with at least one acylating agent
Wherein the acylating agent is selected from the group consisting of acyl anhydrides, acyl halides, and mixtures thereof. The copolymer of claim 1, wherein the at least one vinylamine-containing polymer is a copolymer of partially or fully hydrolyzed poly ( N -vinylformamide), N -vinylformamide and vinylamine, a copolymer of vinylamine and amidine. , N - vinylacetamide and copolymers of vinyl amine, N - vinyl formamide, a terpolymer of vinyl amine and amidine, N - vinylformamide, vinyl amine and vinyl amine-methyl chloride quaternary ammonium salt of a terpolymer, Terpolymers of N -vinylformamide, vinylamine and vinyl alcohol, terpolymers of N -vinylformamide, vinylamine and vinyl acetate, terpolymers of N -vinylformamide, vinylamine and acrylamide, N- vinylformamide, vinyl amine, and a terpolymer of acrylates, N - vinylformamide, vinyl amine, and di terpolymer of allyl dimethyl ammonium chloride, N - vinylformamide, vinylamine The method selected from-containing polymer, mixtures thereof or the group consisting of vinyl trimethoxy silane in the terpolymer, the modified vinylamine. The method of claim 1, wherein the vinylamine-containing polymer comprises partially or fully hydrolyzed poly ( N -vinylformamide). The method of claim 1, wherein the acylated vinylamine-containing polymer has a molecular weight in the range of about 5,000 to about 2,000,000 daltons. a. Performing free radical polymerization of N- vinylformamide in an aqueous solution,
b. Performing alkali hydrolysis to form poly (vinylamine), and
c. Reacting the polyvinylamine with at least one acylating agent
Wherein the acylating agent is selected from the group consisting of acyl anhydrides, acyl halides, and mixtures thereof. The method of claim 5, wherein the polyvinylamine is partially or fully hydrolyzed poly ( N -vinylformamide); Copolymers of N -vinylformamide and vinylamine, copolymers of vinylamine and amidine; Terpolymers of N -vinylformamide, vinylamine and amidine; And mixtures thereof. The method of claim 1, wherein the acylating agent comprises acyl anhydride. 8. The method of any one of claims 1 to 7, wherein the acylating agent comprises an acyl halide. The acylating agent according to any one of claims 1 to 6, wherein the acylating agent is acetic anhydride, propionic anhydride, butyric anhydride, heptanoic anhydride, anhydride, benzoic anhydride, phenylacetic anhydride, crotonic anhydride, chloroacetic anhydride, dichloroacetic anhydride And trifluoroacetic anhydride, heptanoyl anhydride, acyl halide, and mixtures thereof. 7. The process of any one of claims 1 to 6 wherein the acylating agent comprises acetic anhydride. The method of claim 1, wherein the acylating agent comprises propionic anhydride. The acylating agent according to any one of claims 1 to 6 and 9, wherein the acylating agent is acyl chloride, acyl bromide, acetyl chloride, propionyl chloride, butyryl chloride, benzoyl chloride, phenylacetyl chloride, crotonyl chloride, chloro Acetyl chloride and mixtures thereof. The method of claim 1, wherein the acylating agent comprises acetyl chloride. The method of claim 1, wherein the acylating agent comprises propionyl chloride. The method according to any one of claims 1 to 14, wherein the polyvinylamine and acylating agent are reacted for a period of 0.1 to 4 hours. 16. The method of any one of claims 1-15, wherein the polyvinylamine and acylating agent are reacted at pH 7-11. The method according to any one of claims 1 to 16, wherein the polyvinylamine and the acylating agent are reacted at a temperature of 24 to 50 ° C.